Christmas Day is usually the time for the best teams to get serious. Shift up a gear. Make an adjustment or two. Though this was game No. 34 on the schedule, thanks to the season starting two weeks early, the Warriors played like this was the start of a new chapter on the season.

Want to know if the Warriors have cranked it up? Watch them on defense.

Monday, they overwhelmed the Cavaliers. Their intensity and aggression on that end was on another level. The Cavaliers shot 28.6 percent in the first half. In the second quarter, the Warriors held them to 3-for-24 shooting. They goaded LeBron James into an inefficient night: 20 points on 18 shots with seven turnovers.

This was the first time this season the Warriors brought the energy to match the stage, and the retooled Cavaliers — one of the most efficient offenses in the league — couldn’t get anything going.

It matters very little as it pertains to the matchup, especially if the...